Investigation: No engine or propeller problems before crash

Both the left and right engines and the propeller of the Cessna 310R that took off from the Palo Alto Airport on Feb. 17, 2010, and quickly crashed into an East Palo Alto neighborhood appeared to be working at the time of impact, according to a National Transportation Safety Board report released on Friday, Oct. 7.

The cause of the accident, which claimed the lives of three Tesla Motors employees — the pilot Douglas Bourn, a senior electrical engineer and Santa Clara resident; and passengers Andrew Ingram of Palo Alto, an engineer, and Brian Finn of East Palo Alto, a senior manager — is not outlined in the document, known as a "factual report."

But the report confirms eyewitness accounts of the incident and reveals the findings of inspections of the wreckage by the Federal Aviation Administration and makers of the aircraft parts — Cessna Aircraft Company, Teledyne Continental Motors and McCauley Propellers Inc.

Speculation spread after the crash that a mechanical failure might have caused the plane to veer suddenly and strike an electrical tower next to the Bay in East Palo Alto. Examination of the Cessna's left and right engines, however, showed "no pre-impact mechanical anomalies that would have precluded normal operation," the report states.

In addition, "no indications of propeller failure prior to impact were found. Both propellers were rotating at the time of impact ... and were being operated under conditions of power at the time of impact," the report states.

The manufacturers' inspections were conducted under the supervision of the safety-board investigator Josh Cawthra.

The report confirms that visibility at the airport was 1/8 of a mile due to fog, with wind at 5 knots, at 7:49 a.m., less than five minutes before Bourn took off for the Hawthorne, Calif., airport. Because the runway was not visible, he was instructed to take off at his own risk by the air traffic controller.

"(I) understand," Bourn replied.

Toxicology reports performed on Bourn, 56, by the Federal Aviation Administration showed that he had two drugs in his system — an antihistamine known as diphenhydramine and Metoprolol, which is commonly used to treat high blood pressure.

Bourn had filed a flight plan that indicated the six-seat aircraft would make "a right turn to a heading of 060 degrees within 1 mile of the airport." Instead, radar data used to reconstruct the flight path showed the plane turned 45 degrees to the left shortly after takeoff.

The plane first hit the tower and power lines, located a half-mile northwest of the end of airport runway 31. Debris was strewn over almost a 900-foot path. Parts of the plane crashed into homes, yards and Beech Street. No one on the ground was injured.

The report also states that the Cessna was manufactured in 1977 and had new left and right engines installed in August 2004, after which the plane was flown for about 150 hours.

Bourn, who held a commercial pilot certificate as well as a flight instructor certificate, wrote on his last medical certificate application that he had accumulated 2,900 total flight hours in his aviation career, the report states.

The factual report was written by field investigator Cawthra and is the basis for Cawthra to recommend a probable cause of the accident to the National Transportation Safety Board. The board will review the field investigation reports and vote to adopt, reject or modify the probable-cause determination recommended, according to the agency. The investigation is expected to be completed in mid-November.

I'd like to point out to the graphics designer that the piece of land at the top right corner of the graphic is not the "Baylands Nature Preserve", but is actually a small piece of federal property called the "Faber-Laumeister Unit" that is part of the Don Edwards National Wildlife Refuge complex.

The entrance to the property is at the end of Runnymede St. in EPA. The rechannelized San Francisquito Creek is the San Mateo/Santa Clara County Line.

Posted by Mr. Ironic, a resident of Midtown
on Oct 12, 2011 at 9:01 am

So what really happened if it wasnt mechanical failure?

RIP Brian

Posted by Allen Edwards, a resident of Old Palo Alto
on Oct 12, 2011 at 10:58 am

There are other things that could have failed like control flaps. I wonder if they could tell if those things were OK.

Posted by John Galt, a resident of Fairmeadow
on Oct 12, 2011 at 1:27 pm

Check the rudder gust lock. Path describes one caused by a jammed rudder or more likely a rudder lock left in place on takeoff.

Posted by Tired of hot doggers, a resident of East Palo Alto
on Oct 12, 2011 at 4:23 pm

"Path describes one caused by a jammed rudder or more likely a rudder lock left in place on takeoff."

Or a GPS-guided attempt to buzz Brian Finn's house.

Posted by Hmmm, a resident of East Palo Alto
on Oct 12, 2011 at 4:58 pm

Tired, I have wondered the same thing. Even given the house's proximity, the fog made it extra dangerous to fly in that direction - & to fly at all. What a tragic waste of human life, damage to a community & expense that would've been easily avoided by using common sense.

Posted by some guy, a resident of another community
on Oct 12, 2011 at 6:08 pm

The flight path also looks like it heads right toward the Tesla headquarters in San Carlos.

Posted by @ tired, a resident of Midtown
on Oct 13, 2011 at 10:00 am

Only speak on stuff you know. Spreading rumors about a dead man is filthy. The fog was so thick that day I could barely see a mile ahead of me when I was driving, so how the hell would a plane be able to see a house through the fog.

Posted by Tired of hot doggers, a resident of East Palo Alto
on Oct 13, 2011 at 12:44 pm

"how the hell would a plane be able to see a house through the fog"

GPS, sir, GPS.

PAO types love to buzz the 'hood. The inferred track of the plane and the known spread of its debris field are consistent with a trajectory aimed right for a passenger's house. No matter they can't see the house, the point is to lavish the intended victims with engine noise. The fog would conveniently hide the plane.

Posted by @ tired, a resident of Midtown
on Oct 13, 2011 at 3:19 pm

That makes no sense in my opinion. He was a resident of EPA by choice not force and was my neighbor and his baby daughter was in the house at the time. He wasn't the hot dogging type and from what his family said he hated flying in little prop planes but he had to for business. BUT....just to be fair..... Playing devil advocate even if he (someone who cant fly) begged the pilot to buzz over his house wouldn't the pilot have to decline the request due to fog and other dangers? That's like me driving and my passenger (who cant drive) says "can you to do a donut in front of my house" and I agree and wrap the car on a telephone pole. Guess who is going to be held responsible?

Posted by Hmmm, a resident of East Palo Alto
on Oct 13, 2011 at 3:27 pm

If the pilot was smart, he wouldn't have gotten into the plane in the first place. Ditto the passengers. Such a waste. Dumb enough to fly, dumb enough to want to buzz the 'hood. But we don't really know, do we? We just know that the pilot & his passengers took a dumb, unnecessary risk & many have been effected.

Posted by Resident, a resident of Another Palo Alto neighborhood
on Oct 13, 2011 at 3:53 pm

Yes, we don't know what happened. The pilot may have had a heart attack, we don't know.